Instead, police said, the Robeson freshman skipped school with three other girls, all Robeson students, and went to the basement apartment of a three-flat in the 7000 block of South Sangamon Street.

There, at about 1:30 p.m., Baker was fatally shot in the upper torso in what police said might have been an accident. Investigators suspect the shooter is an 18-year-old male who lives in that apartment. He is on parole for a gun conviction and has several other arrests on his record, said Wentworth Area Sgt. Kevin Duffin.

He had not been located by Thursday afternoon, police said.

At the apartment, the suspect was "waving a gun around" when it discharged, hitting Baker, Duffin said. No one else was injured. Officers arriving at the scene did not find the weapon.

Baker was taken to the University of Chicago Hospitals and pronounced dead shortly after 2 p.m.

Duffin said the girls who witnessed the incident told police the shooting was an accident.

"I just hope my daughter is somewhere peaceful," said Kathy Ann Baker, breaking into tears as she stared at a pictureof her daughter. "That's my baby, that's my baby."

Kathy Ann Baker, 40, suffered a pair of strokes about two years ago, leaving her largely unable to care for herself. Along with Jelisa, she lives with her mother and brother.

"She was a quiet little shy girl. She was very easily influenced by others," said Jelisa Baker's grandmother, Mary Baker.

The teen often helped with her mother's care, from feeding her to having simple chats.

"[Her mother] can't walk from point A to B by herself, and I have to come in and tell her her daughter's been shot," Mary Baker said. "It's the hardest thing I've ever had to do in my life. She won't have her to talk with anymore."